Japanese Patent Laying-Open No. 2000-124500 discloses a way of improving a light emitting characteristic of a nitride semiconductor light emitting device, wherein grooves are formed in a GaN layer stacked on a sapphire substrate, the grooves are covered flatly again with a GaN film, and a semiconductor laser device is formed on the covering layer.
Journal of Electronic Materials, Vol. 27, No. 4, 1998, pp. 160–165 describes a way of improving a lasing lifetime of a semiconductor laser device, wherein SiO2 stripe masks as growth inhibiting films are formed on a GaN substrate layer stacked on a sapphire base substrate, a nitride semiconductor underlayer is grown using a selective growth technique, and a semiconductor laser device is formed in a region above the SiO2 mask.
Further, Japanese Journal of Applied Physics, Vol. 39, 2000, pp. L647–L650 describes a way of improving a lasing lifetime of a nitride semiconductor laser device at high output, wherein a nitride semiconductor underlayer is grown by a selective growth technique using SiO2 masks as growth inhibiting films formed in stripe shapes on a GaN substrate, and a semiconductor laser device is formed in a region above the SiO2 mask.
With the nitride semiconductor light emitting devices fabricated as described above, however, it is still desired to further improve the operating lifetime at high output and also improve the product yield thereof. In view of the foregoing, main objects of the present invention are to further improve the operating lifetime at high output of the nitride semiconductor light emitting devices and to improve the product yield thereof by suppressing occurrence of cracks in the devices.